annotate mercurial/archival.py @ 26755:bb0b955d050d

streamclone: support for producing and consuming stream clone bundles

Up to this point, stream clones only existed as a dynamically generated
data format produced and consumed during streaming clones. In order to
support this efficient cloning format with the clone bundles feature, we
need a more formal, on disk representation of the streaming clone data.

This patch introduces a new "bundle" type for streaming clones. Unlike
existing bundles, it does not contain changegroup data. It does,
however, share the same concepts like the 4 byte header which identifies
the type of data that follows and the 2 byte abbreviation for
compression types (of which only "UN" is currently supported).

The new bundle format is essentially the existing stream clone version 1
data format with some headers at the beginning.

Content negotiation at stream clone request time checked for repository
format/requirements compatibility before initiating a stream clone. We
can't do active content negotiation when using clone bundles. So, we put
this set of requirements inside the payload so consumers have a built-in
mechanism for checking compatibility before reading and applying lots of
data. Of course, we will also advertise this requirements set in clone
bundles. But that's for another patch.

We currently don't have a mechanism to produce and consume this new
bundle format. This will be implemented in upcoming patches.

It's worth noting that if a legacy client attempts to `hg unbundle` a
stream clone bundle (with the "HGS1" header), it will abort with:
"unknown bundle version S1," which seems appropriate.

# archival.py - revision archival for mercurial
#
# Copyright 2006 Vadim Gelfer <[e-mail]>
#
# This software may be used and distributed according to the terms of the
# GNU General Public License version 2 or any later version.

from __future__ import absolute_import

import cStringIO
import gzip
import os
import struct
import tarfile
import time
import zipfile
import zlib

from .i18n import _

from . import (
    cmdutil,
    encoding,
    error,
    match as matchmod,
    scmutil,
    util,
)

# from unzip source code:
_UNX_IFREG = 0x8000
_UNX_IFLNK = 0xa000

def tidyprefix(dest, kind, prefix):
    '''choose prefix to use for names in archive.  make sure prefix is
    safe for consumers.'''

    if prefix:
        prefix = util.normpath(prefix)
    else:
        if not isinstance(dest, str):
            raise ValueError('dest must be string if no prefix')
        prefix = os.path.basename(dest)
        lower = prefix.lower()
        for sfx in exts.get(kind, []):
            if lower.endswith(sfx):
                prefix = prefix[:-len(sfx)]
                break
    lpfx = os.path.normpath(util.localpath(prefix))
    prefix = util.pconvert(lpfx)
    if not prefix.endswith('/'):
        prefix += '/'
    # Drop the leading '.' path component if present, so Windows can read the
    # zip files (issue4634)
    if prefix.startswith('./'):
        prefix = prefix[2:]
    if prefix.startswith('../') or os.path.isabs(lpfx) or '/../' in prefix:
        raise error.Abort(_('archive prefix contains illegal components'))
    return prefix

exts = {
    'tar': ['.tar'],
    'tbz2': ['.tbz2', '.tar.bz2'],
    'tgz': ['.tgz', '.tar.gz'],
    'zip': ['.zip'],
    }

def guesskind(dest):
    for kind, extensions in exts.iteritems():
        if any(dest.endswith(ext) for ext in extensions):
            return kind
    return None

def _rootctx(repo):
    # repo[0] may be hidden
    for rev in repo:
        return repo[rev]
    return repo['null']

def buildmetadata(ctx):
    '''build content of .hg_archival.txt'''
    repo = ctx.repo()
    hex = ctx.hex()
    if ctx.rev() is None:
        hex = ctx.p1().hex()
        if ctx.dirty():
            hex += '+'

    base = 'repo: %s\nnode: %s\nbranch: %s\n' % (
        _rootctx(repo).hex(), hex, encoding.fromlocal(ctx.branch()))

    tags = ''.join('tag: %s\n' % t for t in ctx.tags()
                   if repo.tagtype(t) == 'global')
    if not tags:
        repo.ui.pushbuffer()
        opts = {'template': '{latesttag}\n{latesttagdistance}\n'
                            '{changessincelatesttag}',
                'style': '', 'patch': None, 'git': None}
        cmdutil.show_changeset(repo.ui, repo, opts).show(ctx)
        ltags, dist, changessince = repo.ui.popbuffer().split('\n')
        ltags = ltags.split(':')
        tags = ''.join('latesttag: %s\n' % t for t in ltags)
        tags += 'latesttagdistance: %s\n' % dist
        tags += 'changessincelatesttag: %s\n' % changessince

    return base + tags

class tarit(object):
    '''write archive to tar file or stream.  can write uncompressed,
    or compress with gzip or bzip2.'''

    class GzipFileWithTime(gzip.GzipFile):

        def __init__(self, *args, **kw):
            timestamp = None
            if 'timestamp' in kw:
                timestamp = kw.pop('timestamp')
            if timestamp is None:
                self.timestamp = time.time()
            else:
                self.timestamp = timestamp
            gzip.GzipFile.__init__(self, *args, **kw)

        def _write_gzip_header(self):
            self.fileobj.write('\037\213')             # magic header
            self.fileobj.write('\010')                 # compression method
            fname = self.name
            if fname and fname.endswith('.gz'):
                fname = fname[:-3]
            flags = 0
            if fname:
                flags = gzip.FNAME
            self.fileobj.write(chr(flags))
            gzip.write32u(self.fileobj, long(self.timestamp))
            self.fileobj.write('\002')
            self.fileobj.write('\377')
            if fname:
                self.fileobj.write(fname + '\000')

    def __init__(self, dest, mtime, kind=''):
        self.mtime = mtime
        self.fileobj = None

        def taropen(name, mode, fileobj=None):
            if kind == 'gz':
                mode = mode[0]
                if not fileobj:
                    fileobj = open(name, mode + 'b')
                gzfileobj = self.GzipFileWithTime(name, mode + 'b',
                                                  zlib.Z_BEST_COMPRESSION,
                                                  fileobj, timestamp=mtime)
                self.fileobj = gzfileobj
                return tarfile.TarFile.taropen(name, mode, gzfileobj)
            else:
                return tarfile.open(name, mode + kind, fileobj)

        if isinstance(dest, str):
            self.z = taropen(dest, mode='w:')
        else:
            # Python 2.5-2.5.1 have a regression that requires a name arg
            self.z = taropen(name='', mode='w|', fileobj=dest)

    def addfile(self, name, mode, islink, data):
        i = tarfile.TarInfo(name)
        i.mtime = self.mtime
        i.size = len(data)
        if islink:
            i.type = tarfile.SYMTYPE
            i.mode = 0o777
            i.linkname = data
            data = None
            i.size = 0
        else:
            i.mode = mode
            data = cStringIO.StringIO(data)
        self.z.addfile(i, data)

    def done(self):
        self.z.close()
        if self.fileobj:
            self.fileobj.close()

class tellable(object):
    '''provide tell method for zipfile.ZipFile when writing to http
    response file object.'''

    def __init__(self, fp):
        self.fp = fp
        self.offset = 0

    def __getattr__(self, key):
        return getattr(self.fp, key)

    def write(self, s):
        self.fp.write(s)
        self.offset += len(s)

    def tell(self):
        return self.offset

class zipit(object):
    '''write archive to zip file or stream.  can write uncompressed,
    or compressed with deflate.'''

    def __init__(self, dest, mtime, compress=True):
        if not isinstance(dest, str):
            try:
                dest.tell()
            except (AttributeError, IOError):
                dest = tellable(dest)
        self.z = zipfile.ZipFile(dest, 'w',
                                 compress and zipfile.ZIP_DEFLATED or
                                 zipfile.ZIP_STORED)

        # Python's zipfile module emits deprecation warnings if we try
        # to store files with a date before 1980.
        epoch = 315532800 # calendar.timegm((1980, 1, 1, 0, 0, 0, 1, 1, 0))
        if mtime < epoch:
            mtime = epoch

        self.mtime = mtime
        self.date_time = time.gmtime(mtime)[:6]

    def addfile(self, name, mode, islink, data):
        i = zipfile.ZipInfo(name, self.date_time)
        i.compress_type = self.z.compression
        # unzip will not honor unix file modes unless file creator is
        # set to unix (id 3).
        i.create_system = 3
        ftype = _UNX_IFREG
        if islink:
            mode = 0o777
            ftype = _UNX_IFLNK
        i.external_attr = (mode | ftype) << 16L
        # add "extended-timestamp" extra block, because zip archives
        # without this will be extracted with unexpected timestamp,
        # if TZ is not configured as GMT
        i.extra += struct.pack('<hhBl',
                               0x5455,     # block type: "extended-timestamp"
                               1 + 4,      # size of this block
                               1,          # "modification time is present"
                               int(self.mtime)) # last modification (UTC)
        self.z.writestr(i, data)

    def done(self):
        self.z.close()

class fileit(object):
    '''write archive as files in directory.'''

    def __init__(self, name, mtime):
        self.basedir = name
        self.opener = scmutil.opener(self.basedir)

    def addfile(self, name, mode, islink, data):
        if islink:
            self.opener.symlink(data, name)
            return
        f = self.opener(name, "w", atomictemp=True)
        f.write(data)
        f.close()
        destfile = os.path.join(self.basedir, name)
        os.chmod(destfile, mode)

    def done(self):
        pass

archivers = {
    'files': fileit,
    'tar': tarit,
    'tbz2': lambda name, mtime: tarit(name, mtime, 'bz2'),
    'tgz': lambda name, mtime: tarit(name, mtime, 'gz'),
    'uzip': lambda name, mtime: zipit(name, mtime, False),
    'zip': zipit,
    }

def archive(repo, dest, node, kind, decode=True, matchfn=None,
            prefix='', mtime=None, subrepos=False):
    '''create archive of repo as it was at node.

    dest can be name of directory, name of archive file, or file
    object to write archive to.

    kind is type of archive to create.

    decode tells whether to put files through decode filters from
    hgrc.

    matchfn is function to filter names of files to write to archive.

    prefix is name of path to put before every archive member.'''

    if kind == 'files':
        if prefix:
            raise error.Abort(_('cannot give prefix when archiving to files'))
    else:
        prefix = tidyprefix(dest, kind, prefix)

    def write(name, mode, islink, getdata):
        data = getdata()
        if decode:
            data = repo.wwritedata(name, data)
        archiver.addfile(prefix + name, mode, islink, data)

    if kind not in archivers:
        raise error.Abort(_("unknown archive type '%s'") % kind)

    ctx = repo[node]
    archiver = archivers[kind](dest, mtime or ctx.date()[0])

    if repo.ui.configbool("ui", "archivemeta", True):
        name = '.hg_archival.txt'
        if not matchfn or matchfn(name):
            write(name, 0o644, False, lambda: buildmetadata(ctx))

    if matchfn:
        files = [f for f in ctx.manifest().keys() if matchfn(f)]
    else:
        files = ctx.manifest().keys()
    total = len(files)
    if total:
        files.sort()
        repo.ui.progress(_('archiving'), 0, unit=_('files'), total=total)
        for i, f in enumerate(files):
            ff = ctx.flags(f)
            write(f, 'x' in ff and 0o755 or 0o644, 'l' in ff, ctx[f].data)
            repo.ui.progress(_('archiving'), i + 1, item=f,
                             unit=_('files'), total=total)
        repo.ui.progress(_('archiving'), None)

    if subrepos:
        for subpath in sorted(ctx.substate):
            sub = ctx.workingsub(subpath)
            submatch = matchmod.narrowmatcher(subpath, matchfn)
            total += sub.archive(archiver, prefix, submatch)

    if total == 0:
        raise error.Abort(_('no files match the archive pattern'))

    archiver.done()
    return total